Electrical contact.



E. B. CLEMENT.

ELECTRICAL CONTACT. APPLICATION FILED snmaza, 1000.

1,105,489. Patented July 28, 1914.

\ 1L 2 IL 2 I X 2 I 2 k jg )2 P 1L 2 K 1L 2 EL 2 L 2 UNITED STATES PATENT OFFICE.

EDWARD E. CLEMENT, OF WASHINGTON, DISTRICT OF COLUMBIA.

ELECTRICAL CONTACT.

To all whom it may concern Be it known that I, EDWARD E. CLEMENT, a citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in Electrical Contacts, of which the following is a specification, reference being had therein to the accompanying drawing.

My invention relates to contact springs and the contact points thereof, especially to the latter and more especially to contact points used upon the springs of relays or any other spring controlled switches.

The object of the invention is to eliminate the use of expensive platinum rivets which are now used for the contact points of the springs in relays and all other circuit changing springs, which not only reduces the labor and time consumed in placing the contact points on the spring, but reduces the expense of each spring to a minimum.

The invention consists in forcing or rollmg a strip of thin platinum foil across the 25;,

middle of a rectangular blank from which the contact springs are punched. This blank is preferably of German silver, and the springs are punched with their inner ends projecting into the foil-covered portion thereof. After the springs are blanked out, those which ought to have a projecting point receive a center punch on the German silverside of the blank so as to form a platinum covered projection or point on the platinumcovercd side. It will be understood that the platinum may be rolled upon the German silver blank or it ma be placed thereon by plating, or by any ot er wellknown process of covering a base metal with a refined metal. Those springs, which, in use, abut against the punched springs are not operated upon after stamping and are left with a flat platinum face for the contactpoint,

- formed by the center punch in the opposing coating Specifioation of Letters Patent.

Application filed September 29, 1906.

Patented July 28, 1914.

Serial No. 336,737.

tion of a spring and its accompanying contact point, and Fig. 3 is a bottom plan view thereof.

Referring now to the drawings 1 represents a German silver blank and 2 indicates the platinum foil which is rolled, plated or forced thereon in such osition that the contact springs 3 when blhnked out will have their inner ends approximately abutting each other within the platinum coated area. Each spring is punched out in the form shown in Fig. 3 and where they are to have a projecting point they are depressed upon their upper side at 4: to form a projecting platinum covered point 5 upon the opposite side. If the spring is to have no point the depression made by center punching is omitted and the spring left perfectly flat as taken from the blank in Fig. 1. I may reverse the order of operation by rolling the foil on each end of the blank and stamping the springs out in reversed order with their reduced ends 6 meeting with the opposite end of the spring which is alined with it in stamping.

It will be seen from the foregoing that very little platinum is required to properly coat the contact points of the springs, and only 3 operations, com rising very little labor are needed to comp ete the springs for use.

I 11 such modifications as do not depart from the spirit of the invention are considcred within the scope and purview of the appended claim. I

Having thus descrlbed my lnvention, what I claim and desire to secure by Letters Patentis:

A blank for electrical contacts, comprising a sheet of base metal, having a narrow strip of unoxidizable precious m'etal apphed longitudinally. to its central portion and forced into close adherence with its substance, so as to form an integral mass therewith.

, In testimony whereof I afiix my signature in presence of two witnesses.

EDWARD E. CLEMENT.

Witnesses:

J AMES H. MARK, E. EDMONSTON, J r. 

